Manufacturers mandatory bulletins are only mandatory if backed by an AD!!!!!!!!!
But it would be difficult to ignore the word MANDATORY in bright red, inch high, letters on the BTs sent by the manufacturer to owners and operators.
Never mind in court, try explaining why something marked thus wasn't done to the aircraft insurance company. I think the words NULL, and VOID, might feature in any conversation.
Different topic to whether something is a cover-up, or not, which was my point. Also, I presume, totally irrelevant to the subject here, just in case journos mis-read any intonation.